With the scaling down of semiconductor devices, new materials are required. Common materials, like silicon nitride or silicon oxide, need to be deposited in increasingly stringent conditions. For instance, there is a general trend for silicon nitride deposition by Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) at the lowest possible temperature, while keeping a high deposition rate a high film quality. For such processes, the precursor molecule plays a critical role to obtain high quality films with low impurities, and with the suitable conformality properties (from highly conformal for some application, to bottom up fills for other applications).
WO2015/047914 to Sanchez et al. discloses halogen free amine substituted trisilylamine and tridisilylamine compounds and a method of their preparation via dehydrogenative coupling between the corresponding unsubstituted trisilylamines and amines catalyzed by transition metal catalysts.
US2015/376211 to Girard et al. discloses mono-substituted TSA precursors Si-containing film forming compositions.
US2016/0049293 to Li et al. discloses a method and composition comprising same for sealing the pores of a porous low dielectric constant layer by providing an additional thin dielectric film.
US2016/0225616 to Li et al. discloses an apparatus comprising a plurality of silicon-containing layers wherein the silicon-containing layers are selected from a silicon oxide and a silicon nitride layer or film.
WO2016/065221 to Lei et al. discloses compositions and methods using same for forming a silicon-containing film or material.
Molecules lacking Si—C direct bonds are known to yield purer films than molecules having such direct bonds, owing to the low reactivity and high thermal stability of the Si—C bond.
Additionally, silanes having alkoxy groups rarely exhibit proper self limiting growth by atomic layer deposition, and do not allow the formation of silicon nitride films as the oxygen normally remains in the film, and hence are not as versatile as aminosilanes having Si—N bonds in terms of possible applications for thin film deposition. However, while an alkoxy group doesn't appear as a suitable functional group for surface reaction in atomic layer deposition, Si—C free molecules having a Si—O—Si (siloxane) bridge have been proposed and may be used.
Typical Si—C-free silane precursors that have been proposed and used industrially for silicon oxide and silicon nitride thin film deposition are                a—halosilanes, such as dichlorosilane, monochlorosilane, hexachlorodisilane, octachlorotriisilane, di-iodo silane, pentachlorodisilane, etc.        b—perhydrido(poly)silanes such as SiH4, Si2H6 or Si3H8        c—Amino silanes having the general formula SiHx(NR1R2)4-x, such as bis-diethylaminosilanes, tris-dimethylaminosilane, diisopropylaminosilane, bis(ethylmethylamino)silane, tetrakis(ethylamino)silane        d—Amino-disilanes, such as hexakis(ethylamino)disilane, diisopropylaminosilane, diethylaminodisilane.        e—Siloxane, such as disiloxane, hexachlorodisiloxane        f—Trisilylamine, which may be used for a variety of deposition processes such as flowable CVD, thermal low pressure CVD, plasma enhanced CVD, ALD, and plasma enhanced ALD.        g—More recently, other silicon-rich molecules have been proposed such as TSA-Cl or BDSASi. BDSASi for instance has been reported to yield high growth per cycle SiN by PEALD.        
However, molecules enabling higher growth rates at low temperature, whether by ALD, CVD, flowable CVD or other forms of vapor deposition, while maintaining high film purity are still sought to further gain process productivity, or enable depositing in lower temperature conditions than usual precursors.